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oil pressure

Discussion in 'Truck & Equipment Repair' started by ppkgmsy, Jun 18, 2009.

  1. ppkgmsy

    ppkgmsy Member
    from Vermont
    Messages: 73

    Hey guys, got a question about oil pressure on my '87 Chevy 1/2 ton. In the cold weather it would indicate high pressure (near 60psi) on starting, then drop down to normal range after a couple minutes of driving and remain stable at around 30psi. Now that the weather is warmer it sits just below 15psi all the time, never moves. The truck runs great, doesn't burn oil or show any signs of engine problems. I changed the oil last week, using 10-40, but there's no difference in oil pressure. I was thinking there might be a problem with the pressure sending unit. If this is the case, I found it just above the oil filter so it's fairly accessible to change. What do you think?

    I apologize if there's another thread on this. I tried to search but my computer seems to hang up on the search function.
     
  2. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Start with checking the press with an actual mechanical press gage temporarily. The electric gages in the old trucks were never known to be all that accurate (and don't improve with age :D) causing many an owner to replace hard parts for no reason.

    Once you check it with the mechanical gage you find that your factory gage is in fact lying to you; change the sender first. $15 and 10 minutes of your time.
     
  3. ppkgmsy

    ppkgmsy Member
    from Vermont
    Messages: 73

    Thanks B&B. Hooking up a mechanical makes sense. If the sender is the problem, how important is it to get it changed quickly? Does it do anything besides send info to the gage?
     
  4. wild bill

    wild bill PlowSite.com Addict
    Messages: 1,239

    oil

    it let;s you know if you have a major problem ! they dont call them idiot light's for no reason .:salute:
     
  5. ppkgmsy

    ppkgmsy Member
    from Vermont
    Messages: 73

    I was asking if the sender does more than send information to the gague. Does the info influence the actual functioning of the engine in anyway, like through an electrical or vacuum system? Kind of like spark advance. Sorry if this is a dumb question but I figure I'd ask and learn.
     
  6. 2COR517

    2COR517 PlowSite Fanatic
    Messages: 7,115

    I don't believe it does anything other than feed the gauge. Pretty easy to change, you don't even need to drain the oil.
     
  7. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    No worries, it does nothing more than operate the gage.

    Its when it doesn't even do that when you initially worry. :D
     
  8. ppkgmsy

    ppkgmsy Member
    from Vermont
    Messages: 73

    Thanks, all. I took a look at the sender and it's easy to get to, just above the oil filter. I'm going to check it with a mechanical and go from there. I appreciate your help.
     
  9. Milwaukee

    Milwaukee 2000 Club Member
    Messages: 2,180

    I don't know if that one is correct?

    I believe it was near Dist

    Done on 94 Yukon it was very tight to try reach oil sender.
     
  10. ppkgmsy

    ppkgmsy Member
    from Vermont
    Messages: 73

    Must be different designs because the sender on my truck is easy to get to. Doesn't look like the oil filter even needs to be removed.
     
  11. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    It's doesn't, Mill's talking about the wrong sender. ;)
     
  12. Milwaukee

    Milwaukee 2000 Club Member
    Messages: 2,180


    Ok then why we hook oil mechanical and it say right oil pressure and we disconnect plug to make sure it was oil sender so it right. Now you tell me it wrong sender.

    It was behind dist on Chevy 350.
     
  13. Milwaukee

    Milwaukee 2000 Club Member
    Messages: 2,180

    Here pic [​IMG]
     
  14. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Because both of your examples are from the wrong model year. We're talking an '87 here. Your first hand example was a '94...and your pic is from a pre-TBI truck.